diff options
Diffstat (limited to 'src/pkg/net/http/httputil/reverseproxy.go')
| -rw-r--r-- | src/pkg/net/http/httputil/reverseproxy.go | 211 |
1 files changed, 0 insertions, 211 deletions
diff --git a/src/pkg/net/http/httputil/reverseproxy.go b/src/pkg/net/http/httputil/reverseproxy.go deleted file mode 100644 index 48ada5f5f..000000000 --- a/src/pkg/net/http/httputil/reverseproxy.go +++ /dev/null @@ -1,211 +0,0 @@ -// Copyright 2011 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -// HTTP reverse proxy handler - -package httputil - -import ( - "io" - "log" - "net" - "net/http" - "net/url" - "strings" - "sync" - "time" -) - -// onExitFlushLoop is a callback set by tests to detect the state of the -// flushLoop() goroutine. -var onExitFlushLoop func() - -// ReverseProxy is an HTTP Handler that takes an incoming request and -// sends it to another server, proxying the response back to the -// client. -type ReverseProxy struct { - // Director must be a function which modifies - // the request into a new request to be sent - // using Transport. Its response is then copied - // back to the original client unmodified. - Director func(*http.Request) - - // The transport used to perform proxy requests. - // If nil, http.DefaultTransport is used. - Transport http.RoundTripper - - // FlushInterval specifies the flush interval - // to flush to the client while copying the - // response body. - // If zero, no periodic flushing is done. - FlushInterval time.Duration -} - -func singleJoiningSlash(a, b string) string { - aslash := strings.HasSuffix(a, "/") - bslash := strings.HasPrefix(b, "/") - switch { - case aslash && bslash: - return a + b[1:] - case !aslash && !bslash: - return a + "/" + b - } - return a + b -} - -// NewSingleHostReverseProxy returns a new ReverseProxy that rewrites -// URLs to the scheme, host, and base path provided in target. If the -// target's path is "/base" and the incoming request was for "/dir", -// the target request will be for /base/dir. -func NewSingleHostReverseProxy(target *url.URL) *ReverseProxy { - targetQuery := target.RawQuery - director := func(req *http.Request) { - req.URL.Scheme = target.Scheme - req.URL.Host = target.Host - req.URL.Path = singleJoiningSlash(target.Path, req.URL.Path) - if targetQuery == "" || req.URL.RawQuery == "" { - req.URL.RawQuery = targetQuery + req.URL.RawQuery - } else { - req.URL.RawQuery = targetQuery + "&" + req.URL.RawQuery - } - } - return &ReverseProxy{Director: director} -} - -func copyHeader(dst, src http.Header) { - for k, vv := range src { - for _, v := range vv { - dst.Add(k, v) - } - } -} - -// Hop-by-hop headers. These are removed when sent to the backend. -// http://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html -var hopHeaders = []string{ - "Connection", - "Keep-Alive", - "Proxy-Authenticate", - "Proxy-Authorization", - "Te", // canonicalized version of "TE" - "Trailers", - "Transfer-Encoding", - "Upgrade", -} - -func (p *ReverseProxy) ServeHTTP(rw http.ResponseWriter, req *http.Request) { - transport := p.Transport - if transport == nil { - transport = http.DefaultTransport - } - - outreq := new(http.Request) - *outreq = *req // includes shallow copies of maps, but okay - - p.Director(outreq) - outreq.Proto = "HTTP/1.1" - outreq.ProtoMajor = 1 - outreq.ProtoMinor = 1 - outreq.Close = false - - // Remove hop-by-hop headers to the backend. Especially - // important is "Connection" because we want a persistent - // connection, regardless of what the client sent to us. This - // is modifying the same underlying map from req (shallow - // copied above) so we only copy it if necessary. - copiedHeaders := false - for _, h := range hopHeaders { - if outreq.Header.Get(h) != "" { - if !copiedHeaders { - outreq.Header = make(http.Header) - copyHeader(outreq.Header, req.Header) - copiedHeaders = true - } - outreq.Header.Del(h) - } - } - - if clientIP, _, err := net.SplitHostPort(req.RemoteAddr); err == nil { - // If we aren't the first proxy retain prior - // X-Forwarded-For information as a comma+space - // separated list and fold multiple headers into one. - if prior, ok := outreq.Header["X-Forwarded-For"]; ok { - clientIP = strings.Join(prior, ", ") + ", " + clientIP - } - outreq.Header.Set("X-Forwarded-For", clientIP) - } - - res, err := transport.RoundTrip(outreq) - if err != nil { - log.Printf("http: proxy error: %v", err) - rw.WriteHeader(http.StatusInternalServerError) - return - } - defer res.Body.Close() - - for _, h := range hopHeaders { - res.Header.Del(h) - } - - copyHeader(rw.Header(), res.Header) - - rw.WriteHeader(res.StatusCode) - p.copyResponse(rw, res.Body) -} - -func (p *ReverseProxy) copyResponse(dst io.Writer, src io.Reader) { - if p.FlushInterval != 0 { - if wf, ok := dst.(writeFlusher); ok { - mlw := &maxLatencyWriter{ - dst: wf, - latency: p.FlushInterval, - done: make(chan bool), - } - go mlw.flushLoop() - defer mlw.stop() - dst = mlw - } - } - - io.Copy(dst, src) -} - -type writeFlusher interface { - io.Writer - http.Flusher -} - -type maxLatencyWriter struct { - dst writeFlusher - latency time.Duration - - lk sync.Mutex // protects Write + Flush - done chan bool -} - -func (m *maxLatencyWriter) Write(p []byte) (int, error) { - m.lk.Lock() - defer m.lk.Unlock() - return m.dst.Write(p) -} - -func (m *maxLatencyWriter) flushLoop() { - t := time.NewTicker(m.latency) - defer t.Stop() - for { - select { - case <-m.done: - if onExitFlushLoop != nil { - onExitFlushLoop() - } - return - case <-t.C: - m.lk.Lock() - m.dst.Flush() - m.lk.Unlock() - } - } -} - -func (m *maxLatencyWriter) stop() { m.done <- true } |